-LRB- CNN -RRB- -- A proposal by a coalition of Persian Gulf nations to decrease tensions between the government and the opposition in Yemen may have done just the opposite .

One day after the Gulf Cooperation Council released a statement urging Yemen President Ali Abdullah Saleh to transfer powers to his vice president , thousands of protestors returned to the streets Monday for marches and opposition leaders are vowing not to back down .

One eyewitness claims protesters number in the tens of thousands at a anti-Saleh march in Abyan province . CNN could not independently verify the estimate .

`` The youth protesting today are being used by the JMP who are trying to steal the revolution from them , '' Abdu Ganadi , deputy minister of information for the GCC said Monday .

The Joint Meeting Parties bloc , Yemen 's largest opposition group , said the GCC initiative `` does not clearly state that Saleh must step down and only focuses on Saleh 's transferring power . ''

`` We all know the VP is not strong and will never be able to tell Saleh no , even if all his powers are transferred , '' said senior JMP official Hasan Zaid .

The Embassy of the Republic of Yemen in Washington responded to the GCC initiative on Monday in a statement which said Saleh has agreed to transfer powers in accordance with the Yemeni Constitution , which means he will not step down from power until his term ends in 2013 .

`` We will not accept any initiative that will have Saleh still in rule whether the initiative is from the GCC or Europe , '' Zaid said .

The GCC , a six-nation bloc of oil producing countries , met on Sunday in the Saudi Arabian capital , Riyadh , in an effort bring an end to the current political impasse in the country .

`` The opposition wants everything and President Saleh is still the most powerful person in the country , '' GCC 's Ganadi said .

`` The opposition is now the one going against the GCC initiative , '' said Ganadi .

A leading revolutionary attending a march on Monday in Sanaa spoke out against the coalition 's proposal .

`` The youth are not involved in any agreement and in the end , we have the powerful voice , '' said Khaled Anesi . `` No initiative will save Saleh from the crimes he committed against the peaceful youth , '' Anesi said .

In addition to pushing the transfer of power , the GCC 's initiative also called for the formation of a national unity government to be chaired by the opposition .

There was no mention of that proposal in the statement released by the Yemen government .

Last week , Saleh said he welcomes the council 's efforts to help resolve the political crisis in his country . He has said he intends to step down but only under a peaceful and constitutional transition process .

Despite increasing pressure from neighboring countries and opposition groups , the Yemeni government has said calling for Saleh 's departure now is going too far .

Yemen 's president has promised not to run in the next round of elections .

The United States , which has been allied with the Saleh government in its fight against al Qaeda in the Arabian Peninsula , has welcomed past Gulf council initiatives .

`` We strongly encourage all sides to engage in this urgently needed dialogue to reach a solution supported by the Yemeni people , '' Mark Toner , spokesman for the U.S. State Department , said Friday .

`` President Saleh has publicly expressed his willingness to engage in a peaceful transition of power ; the timing and form of this transition should be identified through negotiation and begin soon . ''

Violence and protest have raged in Yemen , where protesters have called for the ouster of Saleh . He has ruled the country since 1978 .

An eyewitness claims hundreds of protesters attended an anti-government march in streets of Sanaa , and other cities across Yemen .

`` We will not be scared to march and make the regime understand that we will not stop until our demands are met , '' student activist Hareth Abdullah said .

`` Every day we increase in power and the regime decreases in power , '' Abdullah said .

High unemployment fuels much of the anger among a growing young population who have suffered from poverty . The protesters also cite government corruption and a lack of political freedom .

`` We will not differ with the revolution youth and we will support them , '' Yahya Abu Osbaa , a senior JMP official said . `` In the end , I can assure you that we will agree on terms , '' Osbaa said .

CNN 's Mohammed Jamjoom , Yousuf Basil , Amir Ahmed and Hakim Almasmari contributed to this report

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NEW : Gulf Cooperation Council accuses the opposition of trying to steal the youth revolution

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NEW : Eyewitness reports tens of thousands gather for anti-Saleh march

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Senior opposition official : `` We will not accept any initiative that will have Saleh still in rule ''

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Yemen president commits to peaceful transfer of power in accordance with Yemeni constitution